electronics (3)


Fixing the HTC One X’s WiFi

A year or so back, I picked up an OEM HTC One X – which at the time was the nicest quad-core phone around that didn’t also happen to be a phablet.

Initially, I had no problems with the device, and the Android Jelly Bean update only brought better performance and a nicer UI.

Unfortunately, at some point, my device must have taken a knock causing the WiFi antenna to be less effective, dropping it’s effective range.

Luckily, this was still more than enough to be usable in most situations and I just left it as it was for best part of 6 months, after which a new update was pushed out from HTC.

Unfortunately (again…) the update changed the behaviour of the radio, causing the effective range for WiFi to drop to around a few feet, through walls, or a dozen or so if I had line of sight – thankfully by this stage I had invested in an ‘unlimited data’ plan, so I could at least leave the phone on HSDPA and still connect to the internet that way, and living in a town meant that most of the time I had more than enough signal that way.

Today,  finally my patience ran out, having struggled with this set up for a few months, and wanted to fix the actual issue – antenna replacement can’t be that hard, right?

 Step One – Getting Inside

One of the first problems with this repair is the nature of the device’s construction.

Phone manufacturers have moved away from the nice, hackable, screwed-together cases of the previous generation of phones, and started building ‘unibody’ cases, whereby the outside of the device is essentially a near-unbroken smooth finish.

Obviously this is a much nicer finish, but it does mean that DIY repairs or tinkering is made much harder.

Thankfully, the folks over at TechRepublic have put together a photo set showing exactly how to crack open the HTC One X’s case and get at it’s juicy innards.

Step Two – What Has Actually Broken?

Next, to find out what was the likely cause of my WiFi woes, I scoured the forums over at XDA Developers (who are consistently awesome!) for anyone with similar problems.

Fortunately (or unfortunately, for them and I) many other One X owners have had problems with the WiFi antenna, and the problem is fairly well documented.

Following the [HARDWARE FAULT] WiFi antenna fault post, over on the One X forums, and digging around in the links therein, I elected to have a go at repairing this myself, rather than trying to get HTC to do a fix for me (how hard can it be?!).

Another user in the thread usefully posted photographs of their own modification to the One X to fix the problem, and it was these that I used to fix mine.

Step Three – Crunch Time

Now that I had a much better idea of what had happened, and a good idea of what to fix, I set to work, cracking the case open and soldering a tiny wire between the defunct antenna connection and the antenna plate.

Soldering a tiny wire to a contact on the antenna plate. Note the additional small drops of solder on each connection point on the unibody... just in case.

Soldering a tiny wire to a contact on the antenna plate.
Note the additional small drops of solder on each connection point on the unibody… just in case.

While the user I had been following had only attached a single wire from the top contact to the antenna, in my case this did not fix the WiFi problem, and I ended up attaching both contacts.

Initially I attached only one contact to the antenna, as per the original post, which did not work in my instance.

Initially I attached only one contact to the antenna, as per the original post, which did not work in my instance.

I ended up connecting both contacts to fix the problem, after some experimentation.

I ended up connecting both contacts to fix the problem, after some experimentation.

With this done, I very carefully reassembled my phone, et voila! Working WiFi again!

Look at all those pretty signals!

Lookit Ma! WiFi signals!

Lookit Ma! WiFi signals!

Hopefully, with that, this is the last I’ll see of the signal issues I’ve been experiencing, and I can finally have my phone back to normal.




SCMES Track Signals – Track Sensors

My intention is to use reed switches for the track sensors, as they fit the needs of ‘non contact’ and ‘cheap’ (ish).

This method only requires a magnet to be fitted to the riding trucks, leaving them electronics (and complication) free. Furthermore, should a guest driver wish to use the track, they can either use one of the club riding trucks, or simply attach a magnet to their own in the appropriate place.

The innards of a riding truck

The riding trucks have this central bracing, providing a nice mount point for our magnets on the underside!

On the subject of the club riding trucks, and the ‘appropriate place’ – mounting the magnets on the trucks should be fairly simple, as they are constructed mainly from mild steel (and thus, magnetic!) so magnets can be stuck anywhere flat on the underside of the truck giving great freedom with regards to fine tuning.

The track sensors themselves will be simple reed switches arranged in parallel such that any switch action will cause an input on the microcontroller to be pulled low.

These ‘sensor bars’ are to be mounted on the inside of the outermost rail (The left-most rail in the image here) as this is where the origonal sensors (microswitches) were mounted by means of bolts through said rail, thus we can re-use the mountings as they were left.

I’m going to write another post covering the design of the `sensor bar’s once I have drawn up the schematics.




SCMES Track Signals

I’m currently designing and building an electronic signalling system for the South Cheshire Model Engineering Society.

A view across the track site

The Track Site

This consists of a set of 10, 3 aspect (red, amber and green) signals to control and 10 track sensors (the nature of which is to be determined) as well as 3 other special-case sensors (two on traverser locking mechanisms, and one station master switch).

The original system was based around a control unit which worked on digital relays and used 36V lamps.
Unfortunately the designer was involved in a car accident and died, leaving the system unfinished, and futhermore, the method of detecting a locomotive passing a signal (microswitches on plates in the track) resulted a far-too-short pulse length to actually trigger the relays.

This left the system in an unfinished state for several years, during which I finished my degree, and now I have time to work on the project.

A development signal's internals

The three high-brightness LEDs inside the head of a signal

The first order of business would be to determine what the control unit is required to drive, in this case high brightness LEDs are used for each aspect, and, although my development unit had a dead red LED, the LEDs could easily be powered by a simple 6v source (in my case, AAA batteries, as can be seen in the larger image).

The LEDs are more than bright enough to be seen far away, so will be acceptable as lamp replacements.

A signal showing all lights on, except red is broken

They're bright (shot taken from an angle to see anything at all!) except for red, in this case!